It is the purpose of this project to study, by biochemical and immunological techniques, the biosynthesis and structural properties of a normal acute phase serum protein, SAA, which has been identified by its cross-reaction with antibodies raised to an amyloid fibril protein, AA. The main topics of present interest are: 1) Structure and conformational properties of SAA; 2) Molecular events of acute phase SAA elevation; 3) Tissue and serum distribution of proteins related to the amyloid fibril protein AA during development of amyloidosis. BIBLIOGRAPHIC REFERENCES: Sipe, J.D., McAdam, K.P.W.J., Torain, B.F., and Pollock, P.S.: Isolation and structural properties of murine SAA-the acute phase precursor of amyloid AA. Immunol. Com. 6,1-12 (1977). Sipe, J.D., McAdam, K.P.W.J. and Uchino, F.: Distribution of protein antigenically related to amyloid fibril protein AA in murine tissues and serum during induction of amyloidosis. Fed. Proc. 36, 3412 (1977).